Electrical switches have existed in which manual actuation of an initial member in a switch results secondarily in the actuation of a contact-bearing switch element to make or break an electrical circuit. Such switch actuation mechanisms are particularly useful where the directly or initially actuated member serves as a first switch and the secondarily actuated member serves as a second switch. One such switch actuation arrangement which is relatively common is found in the switch mechanisms for controlling operation of both the wiper and the washer units of an automotive vehicle, as typified by U.S. Pat. Nos. 2,905,962, 2,993,098 and 3,542,952.
In U.S. Pat. No. 2,905,962 a helical cam surface is formed on the end of a rotatable and reciprocable rod, and the cam surface coacts with a fixed base and a rotatable switch contact such that movement of the rod in one direction rotates the switch contact whereas movement of the rod in the opposite direction does not rotate the switch contact. That switch is mechanically relatively complex.
The U.S. Pat. No. 2,993,098 discloses a switch mechanism having a first biased washer switch actuator which also acts to displace a wiper switch carriage from a first to a second position via a drive arrangement which prevents reverse actuation of the carriage from its first position.
The U.S. Pat. No. 3,524,952 discloses a switch mechanism which includes a rocker-type wiper switch actuator pivotaly supported for actuation between various wiper operating positions and a washer switch actuator slidably supported by the wiper switch actuator for linear movement relative thereto along an axis extending normal to the pivot axis of the wiper switch actuator. While such arrangement is relatively compact, it does not particularly lend itself to applications where various electrical contact surfaces are disposed on a circuit board.
Another form of switch, disclosed in U.S. Pat. No. 3,668,353, utilizes an initial pivoting actuator to transmit a driving force to a slidable carriage on which are mounted electrical contacts. A torsion spring arrangement associated with the input actuator extends into engagement with the slidable carriage for returning the carriage to a neutral position when the input actuating force is released.